<template>

    <div>
        <!--查询表单-->
        <el-form
            :inline="true"
            class="demo-form-inline"
        >

            <!-- 所属分类：级联下拉列表 -->
            <!-- 一级分类 -->
            <el-form-item label="课程类别">
                <el-select
                    clearable
                    v-model="searchObj.subjectParentId"
                    placeholder="请选择"
                    @change="subjectLevelOneChanged"
                >
                    <el-option
                        v-for="subject in subjectNestedList"
                        :key="subject.id"
                        :label="subject.name"
                        :value="subject.id"
                    />
                </el-select>

                <!-- 二级分类 -->
                <el-select
                    clearable
                    v-model="searchObj.subjectId"
                    placeholder="请选择"
                >
                    <el-option
                        v-for="subject in subSubjectList"
                        :key="subject.id"
                        :label="subject.name"
                        :value="subject.id"
                    />
                </el-select>
            </el-form-item>

            <!-- 是否发布 -->
            <el-form-item label="是否发布">
                <el-select
                    clearable
                    v-model="searchObj.status"
                    placeholder="请选择"
                    @change="subjectLevelOneChanged"
                >
                    <el-option
                        value="Normal"
                        label="已发布"
                    />
                    <el-option
                        value="Draft"
                        label="未发布"
                    />
                </el-select>
            </el-form-item>

            <!-- 标题 -->
            <el-form-item>
                <el-input
                    v-model="searchObj.title"
                    placeholder="课程标题"
                />
            </el-form-item>
            <!-- 讲师 -->
            <el-form-item>
                <el-select
                    clearable
                    v-model="searchObj.teacherId"
                    placeholder="请选择讲师"
                >
                    <el-option
                        v-for="teacher in teacherList"
                        :key="teacher.id"
                        :label="teacher.name"
                        :value="teacher.id"
                    />
                </el-select>
            </el-form-item>

            <el-button
                type="primary"
                icon="el-icon-search"
                @click="fetchData()"
            >查询</el-button>
            <el-button
                type="default"
                @click="resetData()"
            >清空</el-button>
        </el-form>
        <!-- 表格 -->
        <el-table
            v-loading="listLoading"
            :data="list"
            element-loading-text="数据加载中"
            border
            fit
            highlight-current-row
            row-class-name="myClassList"
        >

            <el-table-column
                label="序号"
                width="70"
                align="center"
            >
                <template slot-scope="scope">
                    {{ (page - 1) * limit + scope.$index + 1 }}
                </template>
            </el-table-column>

            <el-table-column
                label="课程信息"
                width="470"
                align="center"
            >
                <template slot-scope="scope">
                    <div class="info">
                        <div class="pic">
                            <img
                                :src="scope.row.cover"
                                alt="scope.row.title"
                                width="150px"
                            >
                        </div>
                        <div class="title">
                            <a href="">{{ scope.row.title }}</a>
                            <p>{{ scope.row.lessonNum }}课时</p>
                        </div>
                    </div>

                </template>
            </el-table-column>
            <el-table-column
                label="是否发布"
                align="center"
            >
                <template slot-scope="scope">
                    {{ scope.row.status=='Normal'? '已发布':'未发布' }}
                </template>
            </el-table-column>

            <el-table-column
                label="创建时间"
                align="center"
            >
                <template slot-scope="scope">
                    {{ scope.row.gmtCreate.substr(0, 10) }}
                </template>
            </el-table-column>
            <el-table-column
                label="发布时间"
                align="center"
            >
                <template slot-scope="scope">
                    {{ scope.row.gmtModified.substr(0, 10) }}
                </template>
            </el-table-column>
            <el-table-column
                label="价格"
                width="100"
                align="center"
            >
                <template slot-scope="scope">
                    {{ Number(scope.row.price) === 0 ? '免费' :
      '¥' + scope.row.price.toFixed(2) }}
                </template>
            </el-table-column>
            <el-table-column
                prop="buyCount"
                label="付费学员"
                width="100"
                align="center"
            >
                <template slot-scope="scope">
                    {{ scope.row.buyCount }}人
                </template>
            </el-table-column>

            <el-table-column
                label="操作"
                width="150"
                align="center"
            >
                <template slot-scope="scope">
                    <router-link :to="'/course/info/'+scope.row.id">
                        <el-button
                            type="text"
                            size="mini"
                            icon="el-icon-edit"
                        >编辑课程信息</el-button>
                    </router-link>
                    <router-link :to="'/course/chapter/'+scope.row.id">
                        <el-button
                            type="text"
                            size="mini"
                            icon="el-icon-edit"
                        >编辑课程大纲</el-button>
                    </router-link>
                    <el-button
                        type="text"
                        size="mini"
                        icon="el-icon-delete"
                        @click="removeDataById(scope.row.id)"
                    >删除</el-button>
                </template>
            </el-table-column>
        </el-table>
        <!-- 分页 -->
        <el-pagination
            :current-page="page"
            :page-size="limit"
            :total="total"
            style="padding: 30px 0; text-align: center;"
            layout="total, prev, pager, next, jumper"
            @current-change="fetchData"
        />
    </div>

</template>

<script>
import course from '@/api/course/course'
import teacher from '@/api/teacher/teacher'
import subject from '@/api/subject/subject'

export default {
    data() {
        return {
            listLoading: true, // 是否显示loading信息
            list: null, // 数据列表
            total: 0, // 总记录数
            page: 1, // 页码
            limit: 5, // 每页记录数
            // 查询条件
            searchObj: {
                subjectParentId: '',
                subjectId: '',
                title: '',
                teacherId: ''
            },
            teacherList: [], // 讲师列表
            subjectNestedList: [], // 一级分类列表
            subSubjectList: [] // 二级分类列表,
        }
    },

    created() {
        // 当页面加载时获取数据
        this.fetchData()
        // 初始化分类列表
        this.initSubjectList()
        // 获取讲师列表
        this.initTeacherList()
    },

    methods: {
        removeDataById(id) {
            this.$confirm('此操作将永久删除该课程, 是否继续?', '提示', {
                confirmButtonText: '确定',
                cancelButtonText: '取消',
                type: 'warning'
            })
                .then(() => {
                    course
                        .delCourse(id)
                        .then(result => {
                            if (result.success) {
                                this.$message({
                                    type: 'success',
                                    message: '成功删除课程'
                                })
                                this.fetchData()
                            }
                        })
                        .catch(function(reason) {
                            alert('错误')
                        })
                })
                .catch(() => {
                    this.$message({
                        type: 'info',
                        message: '已取消删除'
                    })
                })
        },
        fetchData(page = 1) {
            // 调用api层获取数据库中的数据
            console.log('加载列表')
            // 当点击分页组件的切换按钮的时候，会传输一个当前页码的参数page
            // 解决分页无效问题
            this.page = page
            this.listLoading = true
            course
                .getPageList(this.page, this.limit, this.searchObj)
                .then(response => {
                    // debugger 设置断点调试
                    if (response.success === true) {
                        this.list = response.data.rows
                        this.total = response.data.total
                    }
                    this.listLoading = false
                })
        },

        initTeacherList() {
            course
                .getListTeacher()
                .then(response => {
                    // 成功
                    if (response.success === true) {
                        this.teacherList = response.data.teacherList
                    }
                })
                .catch(function(reason) {
                    alert('添加课程错误')
                })
        },

        initSubjectList() {
            subject
                .getTreeList()
                .then(response => {
                    // 成功
                    if (response.success === true) {
                        this.subjectNestedList = response.data.list
                    }
                })
                .catch(function(reason) {
                    alert('分类错误错误')
                })
        },

        subjectLevelOneChanged(value) {
            for (let i = 0; i < this.subjectNestedList.length; i++) {
                if (this.subjectNestedList[i].id === value) {
                    this.subSubjectList = this.subjectNestedList[i].children
                    this.searchObj.subjectId = ''
                }
            }
        },

        resetData() {
            this.searchObj = {}
            this.subSubjectList = [] // 二级分类列表
            this.fetchData()
        }
    }
}
</script>
<style scoped>
.myClassList .info {
    width: 450px;
    overflow: hidden;
}
.myClassList .info .pic {
    width: 150px;
    height: 90px;
    overflow: hidden;
    float: left;
}
.myClassList .info .pic a {
    display: block;
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
.myClassList .info .pic img {
    display: block;
    width: 100%;
}
.myClassList td .info .title {
    width: 280px;
    float: right;
    height: 90px;
}
.myClassList td .info .title a {
    display: block;
    height: 48px;
    line-height: 24px;
    overflow: hidden;
    color: #00baf2;
    margin-bottom: 12px;
}
.myClassList td .info .title p {
    line-height: 20px;
    margin-top: 5px;
    color: #818181;
}
</style>
